scholarly journals Electroencephalographic modulations during an open- or closed-eyes motor task

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4492 ◽  
Author(s):  
Sébastien Rimbert ◽  
Rahaf Al-Chwa ◽  
Manuel Zaepffel ◽  
Laurent Bougrain
Keyword(s):  
Motor Cortex ◽  
Motor Task ◽  
Occipital Lobe ◽  
Mu Rhythm ◽  
Beta Band ◽  
Eyes Closed ◽  
Simple Motor Task ◽  
Eyes Open ◽  
Event Related Desynchronisation ◽  
The Right

There is fundamental knowledge that during the resting state cerebral activity recorded by electroencephalography (EEG) is strongly modulated by the eyes-closed condition compared to the eyes-open condition, especially in the occipital lobe. However, little research has demonstrated the influence of the eyes-closed condition on the motor cortex, particularly during a self-paced movement. This prompted the question: How does the motor cortex activity change between the eyes-closed and eyes-open conditions? To answer this question, we recorded EEG signals from 15 voluntary healthy subjects who performed a simple motor task (i.e., a voluntary isometric flexion of the right-hand index) under two conditions: eyes-closed and eyes-open. Our results confirmed strong modulation in the mu rhythm (7–13 Hz) with a large event-related desynchronisation. However, no significant differences have been observed in the beta band (15–30 Hz). Furthermore, evidence suggests that the eyes-closed condition influences the behaviour of subjects. This study gives us greater insight into the motor cortex and could also be useful in the brain-computer interface (BCI) domain.

scholarly journals Reduced interhemispheric and increased intrahemispheric connectivity in schizophrenia brain networks

2019 ◽  
Author(s):  
Jorne Laton ◽  
Jeroen Van Schependom ◽  
Jeroen Decoster ◽  
Tim Moons ◽  
Marc De Hert ◽  
...  
Keyword(s):  
Corpus Callosum ◽  
Resting State ◽  
Right Hemisphere ◽  
Brain Connectivity ◽  
Similarity Measures ◽  
Beta Band ◽  
Auditory Oddball ◽  
Eyes Closed ◽  
Eyes Open ◽  
The Right

AbstractIntroductionBrain connectivity is disturbed in schizophrenia, both during resting state and during active tasks. Schizophrenia is characterised by a corpus callosum pathology and an inability to suppress overstimulation, both of which relate to this disturbed connectivity. We wanted to verify whether network analysis on EEG sensor level can reveal the corpus callosum pathology in schizophrenia.MethodsWe measured 62-channel EEG on 46 schizophrenia patients and 43 healthy controls during eyes-closed and eyes-open resting-state, mismatch negativity and visual and auditory oddball. We assessed connectivity through correlation, coherence and directed transfer function (DTF) in the delta, theta, alpha, low- and high beta bands.ResultsThe coherence and the DTF picked up a consistent pattern of reduced interhemispheric and enhanced intrahemispheric connectivity strength in schizophrenia in the alpha and beta band. This disturbance pattern appeared across all paradigms in the parietal and the occipital region and was generally more pronounced in the right hemisphere.ConclusionsThis is the first study to use multiple similarity measures and different tasks to confirm disturbed brain connectivity on EEG sensor level. We hypothesise that the interhemispheric reductions reflect transcallosal disconnection, while the intrahemispheric increases indicate the inability to suppress the response to stimuli.

Abstract TP441: Neurovascular Coupling is Impaired in Cerebral Amyloid Angiopathy

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Stefano Peca ◽  
Cheryl R McCreary ◽  
Emily Donaldson ◽  
Karla Sanchez ◽  
Anna Charlton ◽  
...  
Keyword(s):  
White Matter ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
White Matter Lesion ◽  
Motor Task ◽  
Neurovascular Coupling ◽  
Occipital Lobe ◽  
Amyloid Angiopathy ◽  
Bold Response ◽  
Cerebral Amyloid

Introduction: Cerebral amyloid angiopathy (CAA) is marked by accumulation of vascular beta-amyloid which is toxic to smooth muscle cells. An animal study and a pilot study in humans suggest decreased vasodilation in CAA. We studied patients with CAA and matched controls to determine whether neurovascular coupling is impaired in CAA. Methods: Patients with CAA and controls underwent task-related fMRI with a visual task (viewing a flashing alternating checkerboard pattern) or a motor task (tapping the fingers of the dominant hand) using a block design, and visual evoked potentials (VEPs). CAA patients were diagnosed by Boston criteria and had normal corrected visual acuity, no visual field deficits and no paresis of the dominant arm. Controls were recruited by community advertising and were matched by gender and age (±5 years) to CAA cases. Results: Eighteen CAA patients (12 M, 6F; 72±7 yrs) and eighteen controls (12 M, 6F; 70±7 yrs) were studied. For the visual task, CAA patients had reduced activity in the occipital lobe (Figure) and lower amplitude of the BOLD response vs. controls (28% reduced, p=0.005). By contrast, for the motor task CAA patients had a similar response of the primary motor cortex vs. controls (9.6% reduced BOLD response, p=0.53). VEP P100 latencies and amplitudes did not differ between CAA and controls (p=0.49 and p=0.74). Lower visual cortex BOLD amplitudes were correlated with greater white matter lesion volumes in CAA (r=-0.66, p=0.003). Conclusions: Neurovascular coupling is impaired in the occipital lobe in CAA. BOLD signal amplitudes are reduced despite normal evoked potentials, suggesting impaired vasodilation. The association with white matter lesion volume raises the possibility that impaired vasodilation may be involved in the pathogenesis of these lesions. BOLD responses in the primary motor cortex in CAA were not reduced, likely reflecting the known posterior predominance of CAA with lesser involvement of the frontal lobe.

EEG TRANSFER ENTROPY TRACKS CHANGES IN INFORMATION TRANSFER ON THE ONSET OF VISION

2012 ◽  
Vol 17 ◽  
pp. 9-18 ◽  
Author(s):  
M. D. MADULARA ◽  
P. A. B. FRANCISCO ◽  
S. NAWANG ◽  
D. C. AROGANCIA ◽  
C. J. CELLUCCI ◽  
...  
Keyword(s):  
Mutual Information ◽  
Information Transfer ◽  
Occipital Lobe ◽  
Transfer Entropy ◽  
The Other ◽  
Information Measures ◽  
Eyes Closed ◽  
Eyes Open ◽  
Almost All ◽  
Nonlinear Correlations

We investigate the pairwise mutual information and transfer entropy of ten-channel, free-running electroencephalographs measured from thirteen subjects under two behavioral conditions: eyes open resting and eyes closed resting. Mutual information measures nonlinear correlations; transfer entropy determines the directionality of information transfer. For all channel pairs, mutual information is generally lower with eyes open compared to eyes closed indicating that EEG signals at different scalp sites become more dissimilar as the visual system is engaged. On the other hand, transfer entropy increases on average by almost two-fold when the eyes are opened. The largest one-way transfer entropies are to and from the Oz site consistent with the involvement of the occipital lobe in vision. The largest net transfer entropies are from F3 and F4 to almost all the other scalp sites.

scholarly journals Relation Between Frontal Alpha Asymmetry and Anxiety in Young Patients with Generalized Anxiety Disorder

PRILOZI ◽  
2015 ◽  
Vol 36 (2) ◽  
pp. 157-177 ◽  
Author(s):  
Aneta Demerdzieva ◽  
Nada Pop-Jordanova
Keyword(s):  
Anxiety Disorder ◽  
Generalized Anxiety Disorder ◽  
Frontal Region ◽  
Generalized Anxiety ◽  
Alpha Power ◽  
Alpha Asymmetry ◽  
Eyes Closed ◽  
Frontal Alpha Asymmetry ◽  
Eyes Open ◽  
The Right

Abstract Frontal alpha asymmetry (the relative difference in power between two signals in different hemispheres) has been suggested as biomarker for anxiety. The goal of this study was to evaluate alpha asymmetry in the frontal region for young people (7-18 years) with generalized anxiety disorder, diagnosed according to two statistic manuals (DMS-IV-R and ICD-10), the medical history and the neuropsychological assessment. The QEEG recording and analysis of the obtained results from alpha spectra power and log of alpha spectra power are made in four conditions (eyes open, eyes closed, VCPT and ACPT). The obtained results for alpha power in general showed higher cortical activity in the right hemisphere, associated with negative emotions. The calculated alpha asymmetry separate for eyes open, eyes closed, VCPT and ACPT conditions showed the right activation in all four conditions. In addition, the right frontal asymmetry was specific for the Fp1-Fp2 region, while a greater left frontal activation was recorded for the F7-F8 region. The log of alpha power in general was additionally analyzed. The calculated asymmetry score in general (in a way that the left log transformed score was subtracted from the right) confirmed a greater right activation. Testing the power of the whole alpha band (μV2) in general, for all four conditions and for frontal region confirmed the right alpha asymmetries in all participants. The right alpha asymmetry in the frontal region was specific only for the Fp1-Fp2 region (frontopolar region). The only greater left frontal activation was registered between the F7-F8 region. Our findings are supported by many other studies using specific localization methods like fMRI or LORETA source localization.

Reduced activation and altered laterality in two neuroleptic-naive catatonic patients during a motor task in functional MRI

1999 ◽  
Vol 29 (4) ◽  
pp. 997-1002 ◽  
Author(s):  
G. NORTHOFF ◽  
D. F. BRAUS ◽  
A. SARTORIUS ◽  
D. KHORAM-SEFAT ◽  
M. RUSS ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Motor Cortex ◽  
Pulse Sequence ◽  
Motor Task ◽  
Contralateral Side ◽  
Magnetic Resonance Images ◽  
Healthy Controls ◽  
Functional Magnetic Resonance ◽  
Normal Pattern ◽  
The Right

Background. Catatonia, a symptom complex with motor, affective and cognitive symptoms seen in a variety of psychotic conditions and with organic disease, was examined using a motor task using functional magnetic resonance imaging (fMRI).Methods. Two acute catatonic patients and two age- and sex-matched healthy controls performed sequential finger opposition (SFO) after being medicated with 2 mg of lorazepam (i.v.). Functional magnetic resonance images were collected using a gradient echo pulse sequence (EPI).Results. Patients with catatonia showed reduced motor activation of the contralateral motor cortex during SFO of the right hand, ipsilateral activation was similar for patients and controls. There were no differences in the activation of the SMA. During left hand activation the right-handed catatonic patients showed more activation in the ipsilateral cortex, a reversal from the normal pattern of activation in which the contralateral side shows four to five times more activation than the ipsilateral side.Conclusions. In catatonic patients there is a decreased activation in motor cortex during a motor task compared to matched medicated healthy controls. In addition activation of the non-dominant side, left-handed activity in right-handed patients, results in a total reversal of the normal pattern of lateral activation suggesting a disturbance in hemispheric localization of activity during a catatonic state.

scholarly journals Daytime Neurophysiological Hyperarousal in Chronic Insomnia: A Study of qEEG

2020 ◽  
Vol 9 (11) ◽  
pp. 3425
Author(s):  
Da Young Oh ◽  
Su Mi Park ◽  
Sung Won Choi
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Chronic Insomnia ◽  
Beta Band ◽  
Eyes Closed ◽  
Eyes Open ◽  
Quantitative Electroencephalogram ◽  
High Beta ◽  
Insomnia Symptoms ◽  
Band Activity

Background: The hyperarousal model demonstrates that instability of sleep-wake regulation leads to insomnia symptoms and various neurophysiological hyperarousal states. Previous studies have shown that hyperarousal states that appear in chronic insomnia patients are not limited to sleep at nighttime but are stable characteristics that extend into the daytime. However, this phenomenon is mainly measured at bedtime, so it hard to determine whether it is maintained throughout a 24 h cycle or if it just appears at bedtime. Methods: We examined the resting state qEEG (quantitative electroencephalogram) and ECG (electrocardiogram) of chronic insomnia patients (n = 24) compared to good sleepers (n = 22) during the daytime. Results: As compared with controls, participants with insomnia showed a clearly high beta band activity in eyes closed condition at all brain areas. They showed a low frequency band at the frontal area; high frequency bands at the central and parietal areas were found in eyes open condition. Significantly higher heart rates were also found in the chronic insomnia group. Conclusion: These findings suggest that chronic insomnia patients were in a state of neurophysiological hyperarousal during the middle of the day due to abnormal arousal regulation.

scholarly journals Associations between EEG functional brain connectivity and a cognitive reserve proxy in healthy older adults

2019 ◽  
Author(s):  
Bahar Moezzi ◽  
Louise M. Lavrencic ◽  
Mitchell R. Goldsworthy ◽  
Scott Coussens ◽  
Hannah A.D. Keage
Keyword(s):  
Prefrontal Cortex ◽  
Functional Connectivity ◽  
Cognitive Reserve ◽  
Medium Effect ◽  
Theta Band ◽  
Healthy Older Adults ◽  
Eyes Closed ◽  
Medium Effect Size ◽  
Eyes Open ◽  
The Right

AbstractCognitive reserve is a concept that explains individual differences in vulnerability to cognitive impairment due to age and dementia-related brain changes. Mechanisms underlying the cognitive reserve effect are poorly understood. We investigated associations between a comprehensive cognitive reserve proxy (Lifetime Experiences Questionnaire/LEQ) and functional connectivity of the prefrontal cortex across the whole scalp, covarying for the level of current cognitive functioning (Addenbrookes Cognitive Examination Revised/ACE-R), using multiblock parallel and orthogonalized partial least squares regression. EEG data were collected from 34 healthy older adults (63 to 83 years) in eyes-open and eyes-closed resting-states, and during 0-back and 1-back tasks. Functional connectivity was estimated using imaginary coherence in the theta and alpha frequency bands, as these bands have been heavily implicated in cognitive ageing, attention and executive function. We found three clusters of electrodes where the absolute values of the regression coefficient were above threshold when covarying for ACE-R: (1) a cluster approximating the right frontocentral region during the eyes-open condition in the theta band with seed electrodes approximating the left prefrontal cortex with positive associations of medium effect size; (2) a cluster approximating the right parietotemporal region during the 0-back task in the theta band with seed electrodes approximating the right prefrontal cortex with negative associations of medium to large effect sizes; and (3) a cluster approximating the occipitoparietal region in the eyes-closed condition in the alpha band with seed electrodes approximating the left prefrontal cortex with negative associations of medium effect size. These relationships between a cognitive reserve proxy and functional connectivity, within key networks and frequency bands associated with attention and executive function, may reflect greater neural capacity and efficiency.

scholarly journals The effects of long-term exercise training on the neural control of walking

2021 ◽  
Author(s):  
Morteza Yaserifar ◽  
Ziya Fallah Mohammadi ◽  
Sayed Esmaiel Hosseininejad ◽  
Iman Esmaili Paeen Afrakoti ◽  
Kenneth Meijer ◽  
...  
Keyword(s):  
Neural Control ◽  
Treadmill Walking ◽  
Muscle Synergies ◽  
Muscle Coordination ◽  
Overground Walking ◽  
Eyes Closed ◽  
Gait Parameters ◽  
Eyes Open ◽  
The Right

AbstractHow does long-term training modify the neural control of walking? Here we investigate changes in kinematics and muscle synergies of the lower extremities in 10 soccer players and 10 non-athletes while they walked with eyes open or closed either overground or on a treadmill. Electromyography (EMG) was acquired from eight muscles of the right leg and foot switch data were recorded to extract temporal gait parameters. Muscle synergies were extracted using non-negative matrix factorisation for each participant and condition separately and were then grouped using k-means clustering. We found that both the cycle and stance duration were longer during treadmill walking compared to overground walking, whereas the swing phase was longer during the eyes-open compare to the eyes-closed condition. On average, more synergies were expressed in the athlete compared to the non-athlete group and during treadmill compared to overground walking. We found that synergy 2 involved in ankle plantarflexion was more often activated in athletes than in non-athletes. We did not find statistical group differences for the synergy metrics but several differences were observed between conditions: peak activation of synergy 5 (VM and VL muscles) increased during overground walking compared to treadmill walking. In addition, reduced activation of synergy 3 (TA muscle) and synergy 4 was observed during eyes-closed compared to eyes-open walking. These findings suggest that during walking long-term training results in greater flexibility of muscle coordination by recruiting additional synergies, but we found no evidence that long-term training affects the activation patterns of these synergies.

scholarly journals Hemispheric differences in altered reactivity of brain oscillations at rest after posterior lesions

2021 ◽  
Author(s):  
Jessica Gallina ◽  
Mattia Pietrelli ◽  
Marco Zanon ◽  
Caterina Bertini
Keyword(s):  
Visual System ◽  
Resting State ◽  
Visual Processing ◽  
Right Hemisphere ◽  
Oscillatory Activity ◽  
Alpha Oscillations ◽  
Eyes Closed ◽  
Eyes Open ◽  
The Right ◽  
Theta Range

AbstractA variety of evidence supports the dominance of the right hemisphere in perceptual and visuo-spatial processing. Although growing evidence shows a strong link between alpha oscillations and the functionality of the visual system, asymmetries in alpha oscillatory patterns still need to be investigated. Converging findings indicate that the typical alpha desynchronization occurring in the transition from the eyes-closed to the eyes-open resting state might represent an index of reactivity of the visual system. Thus, investigating hemispheric asymmetries in EEG reactivity at the opening of the eyes in brain-lesioned patients may shed light on the contribution of specific cortical sites and each hemisphere in regulating the oscillatory patterns reflecting the functionality of the visual system. To this aim, EEG signal was recorded during eyes-closed and eyes-open resting state in hemianopic patients with posterior left or right lesions, patients without hemianopia with anterior lesions and healthy controls. Hemianopics with both left and right posterior lesions showed a reduced alpha reactivity at the opening of the eyes, suggesting that posterior cortices have a pivotal role in the functionality of alpha oscillations. However, right-lesioned hemianopics showed a greater dysfunction, demonstrated by a reactivity reduction more distributed over the scalp, compared to left-lesioned hemianopics. Moreover, they also revealed impaired reactivity in the theta range. This favors the hypothesis of a specialized role of the right hemisphere in orchestrating oscillatory patterns, both coordinating widespread alpha oscillatory activity and organizing focal processing in the theta range, to support visual processing at the opening of the eyes.

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